High temperature seals are necessary in many industrial applications. For example, the shroud damper system of a gas or steam turbine, which is exposed to the high operating temperatures of the turbine environment, requires a damage tolerant sealing scheme that is robust against leakage and able to meet long-term durability goals. More specifically, the metal damper is used to dampen specific vibratory modes on the shroud assembly and requires a high temperature seal to prevent gas from escaping the main flowpath of the turbine and, thereby, decreasing the efficiency of the unit.
Conventional seals have proven to be unsatisfactory for such applications. For example, conventional rope seal concepts utilize a single “rope” of ceramic fibers to effect a seal against the component. However, the rope does not provide effective sealing due to its porous structure. Moreover, the chemical and mechanical degradation that occurs to the rope seal during usage further compromises the integrity of the seal such that the rope seal fails to meet long-term durability goals. Further, hot gas path temperatures in gas turbines continue to increase. As this occurs, the use of conventional, metallic seals becomes quite limited.
Accordingly, there is a need for an improved high temperature sealing system that provides an effective and robust seal against leakage while also being able to withstand a corrosive, high temperature environment, such as the environment found within the flowpath of a gas turbine. More specifically, there is a need for a high temperature sealing system that is effective in the shroud damper system of gas turbines.